Electric disconnecting device



L. J. LINDE ELECTRIC DISGONNECTING DEVICE Oct. 17, 1939;

Filed Dec. 12, 1936 Irwverw-borm Lerward J'Linde,

by HI 'btorney Patented 17, 1939 anaemic DISCONNEGTING DEVICE Leonard J. Iiinde,

General Electric Company,

New York Drexel HilL. Pa., assignor to a corporation of Application December 12, 1936, Serial No. 115,642

2 Claims.

My invention relates to electric disconnectin devices, more particularly to those of the plug and socket type having, for example, application toelectric switchgear of the draw-out type which is electrically eflicient, readily adaptable to varying operating conditions and simple and rugged in construction.

In accordance with, my invention, the socket member of the disconnecting contact device, which may be fabricated or consist of a unitary member, is tubular or cylindrical in form and has substantially circular line contact with both the stationary and movable contactstructures respectively so that efflcient electrical contact is maintained by said socket member at both contacts notwithstanding appreciable misalinement of said structures.

More specifically, the cylindrical socket member in one application thereof is provided with interleaving slots extending from the opposite ends thereof for insuring a high degree of resiliency and compactness of design. Where compactness of design is an essential factor, the cylindrical member can be found by a plurality of separate fingers biased so as to interconnect.

the coacting pair of contacts in line contact eneasement, I

My invention will be more fully set forth in the following description referring to the accompanying drawing, and the features of novelty which characterize my invention 'will be pointed 4 out with particularity in the claims annexed to and forming a part of this specification.

Referring to the drawing, Fig. 1 is an elevational view of electric switchgear of the drawout type having disconnecting devices embody- 45 ing the present invention; Fig. 2 is an enlarged longitudinal view partly in section of one of the sets of sconnecting contacts shown by Fig. 1 in the o n-clrcuit position and Fig. 3 is a sectional view taken along the line 3-3 of Fig. 2. 50 A particular form of draw-out type switch- .gear to which the present invention is applicable is illustrated by Fig. 1 wherein a pair of stationary circuit terminals generally indicated at I and 2 co'act with a relatively movable circuit in- 56 terrupting unit 3. The unit 3 normally controls an electric power circuit including the terminals i and 2.

The circuit breaker unit 3 in the present instance comprises' a switch panel or base 4 on which is mounted a suitable power interrupting device, such as a conventional magnetic blowout air circuit breaker, for example. As the details of the circuit breaker form no part of the present invention, specific disclosure thereof is believed to be unnecessary for an adequate and '10 clear understanding of the invention.

As in the case of'conventional draw-out type switchgear, the circuit breaker unit 3 is bodily movable between connected and disconnected positions with respect to the circuit terminals i 15 and Z, and is guided and supported for horizontal reciprocal movement by means of a pair of stationary guide rails 5, between which the unit is positioned, and coacting rollers 6 mounted on the movable unit. Mounted in and extend- 20 ing through the base panel 4 of the breaker unit are the breaker terminals I and 8 corresponding to the terminals l and 2 respectively which are suitably mounted on the stationary supporting panel 9. The guide rails 5,'which support the 25 unit 3 in cantilever fashion, are suitably braced as at 5'.

The disconnecting devices for effecting the actual electrical contact between the circuit breaker unit 3 and the stationary terminals I 30 and 2 are indicated at Ill and H respectively. Figs, 2 and 3 illustrating in greater detail the specific construction. of the disconnecting contacts. Sincev the contacts are identical in design the disconnect device at ill for intercon- 36 necting the terminals I and 'I will be described.

The disconnecting device consists essentially of tubular cylindrical member I! composed of copper or other suitable conducting material open at the opposite ends for receivable contact 40 elements l3 and i4 constituting parts of the stationary and movable terminals 'respectively. The contact surfaces of the contact elements l3 and I4 coacting with the interior cylindrical contact surface of the member ii are of substantially spherical formation so that circular line contact is maintained at both ends of the member l2 notwithstanding appreciable misalinement of the terminals l and I. In other Words, the contact connection at oppositeends of the cylindrical member I2 is in a certain sense A analogous to a universal joint.

For the purpose of horizontally mounting the member I! on the terminal i, there is provided a reduced portion 15 forming an extension of 5 larly to Fig. 3, the member l2-is looselyconnected to the ring ll, such as by peripherally spaced screws 20 which are provided with extensions 2i having a sliding fit in corresponding apertures 22 formed in the ring it. With this arrangement the ring II, which is located in the annular groove ll, suitably supports the member I! while allowing a limited universal movement thereof at the coacting contact surfaces of the members I! and II.

Resiliency at thecoacting contact surfaces is accomplished in the present instance by providing slots 23 in the member I! extending longitudinally from the opposite ends of the member I! as illustrated, the slots being interleaved 29 intermediate the endsof the member II, the extent of interleaving depending upon the degree of resilience and mechanical strength desired.

Accordingly, the unitary contact member I: ap-v proaches the dptimum with respect to compactg5 ness of design in combination with a high degree of resiliency. Resilience and adequate contact pressure at the restricted contact area are further insured by garter springs 24 positioned at the opposite ends of the member i2.- As illus- 30 trated by Fig. 2, the springs are suitably positioned by axially spaced screw heads- 28 which said ring on said terminal, and means interconare suitably disposed at the outer periphery of the member l2.

In the operation of the disconnecting device 35 above-described, the circuit breaker unit 8 in to the connected position forces the contact ll into,the cylindrical member I! g inst the friction due to the bias of the springs 24 and the inherent resiliency of the member if. 40

' guiding the contact it in case of inaccurate alinement of the terminals l and l. 7

Assuming improper alinement within practical limits, the member I! is simply tilted in the di- 45 reetlon ofmisalinement, the contact between members I! and I! at the terminal] being substantially unaii'ected except that the line of contact engagement is shifted somewhat along the spherical contact surface. Inorder to ,insure maximum electrical eflicieney, the contactmembers l2, II and I4 can be silver plated at the The member I: issuitably beveled as at I! for when the breaker unit 3 is to be disconnected, the breaker is first opened in accordance with well-known practice and the unit then withdrawn along the guide rails 5 to its disconnected position. In order to provide a more compact 5 design, the guide rails 5 are provided with fold-' ing extensions 5"; this feature forming no part of the present invention.

It should be understood that my invention is not limited to specific details of construction and 10 arrangement thereof herein illustrated, and that changes and modifications may occur to one skilled in the art without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric disconnecting device for interconnecting terminals of a power circuit comprising a tubular conducting member open at the opposite ends thereof, contact elements connected to said terminals respectively adapted to extend within opposite ends of said tubular member and engage the interior contact surfaces thereof, each of said elements having substantially spherical contact surfaces for making uniform pressure, line contact with the coasting surfaces of said tubular member, and means for mounting said tubular member for limited universal movement with respect to one of said terminals inculding a ring member surrounding and loosely fitted on said terminal, means for locking necting said tubular member and said ring 2. An electric disconnecting device for interconnecting relatively -movable terminals of a power circuit comprising a tubular conducting member open at its opposite ends, contact elements connected to said terminals respectively adaptedto extend within the opposite ends of 40 said tubular member and engage the interior contact surfaces thereof, and means for mount-- ing said tubular members for limited universal movement with respect to one of said terminals including aring member surrounding and loosely fitted on said terminaLmeans for loclclng said ring onsaid terminal, and peripherally spaced members interconnecting said-tubular member and said ring member.-

LEONARD J. LINDE.

coacting contact surfaces, particularly where v eavy currents are involved. 

